Landslide Hazard Mapping Using Geo-Environmental Parameters—A Case Study on Shimla Tehsil, Himachal Pradesh

Abstract

A landslide is defined as the movement of a mass of rock, debris, or earth down a slope. Landslides are a type of “mass wasting,” which denotes any down-slope movement of soil and rock under the direct influence of gravity. The present research paper is an attempt to assess the vulnerability of Shimla Tehsil to landslides. Five causative factors such as land use and land cover, slope morphometry, relative relief, lithology, and hydrogeology are used to calculate the landslide vulnerability. Survey of India, Geological Survey of India Toposheets, ASTER GDEM, and LANDSAT 8 OLI/TIRS sensor were used as data sources. The causative factors were analyzed and processed in GIS environment. The weightages were assigned based on ratings derived from Bureau of Indian Standards, pp 1–19, 1998, [1] for macroscale landslide mapping. Finally, the factors were integrated using weighted overlay method to produce final vulnerability map. The final output was categorized into four types based on the Total Hazard Estimated Index (THED) ranging from very low hazard to high hazard. The output reveals that the entire Shimla Tehsil falls under four categories of vulnerability ranging from very low vulnerability to high vulnerability. 62.02% of the Shimla Tehsil is prone to low hazard followed by very low at 26.10%, moderate at 11.55%, and high covering only 0.32%. Most of the major settlements are located along moderately vulnerable area.